Electron microscopy of the juxtaglomerular apparatus in young fowl fed a salt deficient diet

Kidneys from young fowl fed a salt deficient diet for up to five weeks were examined under the electron microscope. The presence of maculae densae (MD) were confirmed and the concentrations of nuclei in the MD and the remainder of the distal convoluted tubules were compared. In the proximal convoluted tubules, salt deprivation caused mitochondrial changes, an increase in intranuclear and cytoplasmic lipid and the deposition of urates. Regional thickening of the glomerular basement membrane was observed in many kidneys. In the normal kidney, there is an age dependent increase in the juxtaglomerular granules in the cortical glomeruli (P less than 0.02), but not in the juxtamedullary glomeruli. In salt deprived birds, juxtaglomerular granules were increased in the juxtamedullary glomeruli (P less than 0.01) but not in the cortical glomeruli. Salt deprivation also caused a significant reduction in bodyweight after five weeks (P less than 0.002) and increases in heterophil (P less than 0.02) and monocyte (P less than 0.05) counts in the blood.     

Incidence and new records of Mycosphaerella species within a Eucalyptus globulus plantation in Western Australia

Eucalyptus globulus is the predominant exotic hardwood plantation species in Western Australian (WA), and is often planted adjacent to native eucalypt forests. The increase in number of Mycosphaerella species associated with Mycosphaerella leaf disease (MLD) in E. globulus plantations in WA in the past decade has raised concern about the possible movement of pathogens between the native forests and plantations. In order to determine whether the introduction of new E. globulus genetics into WA may have further exacerbated this situation, juvenile and adult foliage were taken from a genetics trial near Albany, WA consisting of 60 full-sib families and Mycosphaerella species identified using morphological and molecular tools. Eleven species of Mycosphaerella were identified from one plantation: Mycosphaerella fori (Pseudocercospora fori) and Mycosphaerella ellipsoidea are new records for Australia; Mycosphaerella tasmaniensis (Passalora tasmaniensis) and Mycosphaerella suttoniae (Kirramyces epicoccoides) are new records for WA; and Mycosphaerella nubilosa, Mycosphaerella cryptica, Mycosphaerella marksii, Mycosphaerella molleriana, Mycosphaerella lateralis, Mycosphaerella aurantia and Mycosphaerella parva, previously recorded for WA. The most frequently isolated species from juvenile foliage was M. marksii (77%) followed by M. nubilosa (33%). M. nubilosa was most frequently isolated from adult leaves (88%) followed by M. parva (7.5%). Three species, M. molleriana, M. lateralis and M. cryptica, were only isolated from adult leaves while M. ellipsoidea was only isolated from juvenile leaves. These records increase the number of known Mycosphaerella species from eucalypts in WA from 10 to 13. The increase in the number, distribution and impact of Mycosphaerella species contributing to MLD in WA is of concern both to the potential productivity of the plantations and the biosecurity of native WA Eucalyptus species. Continued monitoring of the plantation estate is required to understand the dynamics of the host–pathogen interactions.     

Nonemployment Income and the Economic Base of Michigan Counties: 1959–1986

ABSTRACT Despite the fact that nonemployment income makes up approximately one-third of all personal income, its impact on local area economies has not been closely examined. This study uses Michigan county data to examine the impact of nonemployment income on nonbasic income over a twenty-seven-year period. This impact is compared to the impact of basic income by employing regression analysis to estimate comparative multiplier effects for both types of income. Nonemployment income is found to have a significant impact on nonbasic income, particularly in metropolitan and nonmetropolitan urban counties, where its impact appears to be stronger than that of basic income.     

Inheritance of the stay-green trait in tropical maize

Stay-green maize genotypes have been associated with tolerance to biotic and abiotic stresses, including tolerance to drought, and to stalk and root lodging, but there is limited information on its inheritance. Thus, this research was conducted to study the inheritance of the stay-green trait using both conventional analysis and QTL mapping of the Design III in a tropical maize population developed from two inbred lines genetically divergent for this trait. Two-hundred and fifty F₂ plants were genotyped with 177 microsatellite markers, and their backcrossed progenies to both parental inbreds were evaluated at three locations. Ten plants per plot were assessed 120 days after sowing and the plot means scores for stay-green, adjusted for days to silking emergence, were used for analysis. The additive variance was larger than the dominance variance, the genetic by location interaction variance presented a high magnitude, and the heritability coefficient on a plant-basis a low magnitude. Seventeen QTL were mapped, most of them were clustered on four chromosomes and accounted for by 73.08 % of the genetic variance. About half of the QTL interacted with location, and the average level of dominance was partial dominance. The additive effects were larger than the dominance effects; the latter were not unidirectional, so that heterosis could not be exploited in crosses. Procedures for marker-assisted selection to increase the level of stay-green are discussed and an approach is suggested for using both stable and non-stable QTL in a marker-assisted backcross program.     

Stability analysis of yield and aflatoxin accumulation resistance in maize using GGE biplot

Journal of Crop Science and Biotechnology - Maize (Zea mays L.) is the most important cereal crop in sub-Saharan Africa. However, its production is constrained by many factors including low yields...     

Assessment of Genetic Diversity for Grain Yield and Yield Component Traits in Some Genotypes of Rice (Oryza Sativa L.)

Journal of Crop Science and Biotechnology - Even though there are abundant rice genetic resources, only a fraction is used in breeding programs leading to a narrow genetic base for improved...     

Ultrastructural demonstration of mitochondrial calcium overload in myocardial cells from broiler chickens with ascites and induced hypoxia

Two groups of young broiler chickens, namely, naturally occurring field cases of ascites and those with an induced hypoxia, were used in an ultrastructural study to examine the localisation and distribution of intracellular Ca²⁺ in cardiomyocytes. Age-matched healthy flockmates were used to control each group. Deposits of Ca²⁺ were located extensively in the mitochondria, sarcoplasmic reticulum and Golgi apparatus and sometimes in the myocyte and endothelial cell nuclei of both groups of birds. The results suggest that the cells from the hearts of the ascitic broilers may have been exposed to hypoxia since a large proportion of control material showed no Ca²⁺ activity in either mitochondria or nuclei. The presence of a Ca²⁺ overload in the mitochondria of cardiomyocytes from ascitic birds reared at low altitude or sea level suggests that these broilers were suffering from the deleterious effects of chronic hypoxia due to poor or reduced oxygen use.     

Studies of parvovirus vaccination in the dog: the performance of live attenuated feline parvovirus vaccines

The performance of three live attenuated feline parvovirus vaccines licensed for use in the dog was studied. At the end of the primary vaccination course 67 per cent of dogs had inadequate antibody levels (less than or equal to 32) as measured by a haemagglutination inhibition test. Interference by maternal antibody accounted for some of the failures but the fact that there was no significant difference in performance between dogs vaccinated at 12 weeks or 16 weeks of age indicated that maternal antibody was not the only factor.     

Determination of total lipid and lipid subclasses in meat and meat products

Current interest in physiological and nutritional activities of the sterol, polyunsaturated fatty acid, and polar lipid fractions of meats and other foods indicates that analytical methods for lipids should be evaluated on their ability to recover and quantitate these classes. Current methods of lipid isolation furnish an extract that is dependent on the solvent(s) used, the type of food material, the temperature of extraction, and the relative proportions of the lipid classes present. Extraction with ethers or other relatively nonpolar solvents removes principally the neutral fats and nonpolar lipids. For an approximation of the crude fat content, such extraction is often sufficient, because the nonpolar fraction generally constitutes over 90% of the total lipids present. The polar lipids include the biochemically important (omega-3) and (omega-6) polyunsaturated fatty acid classes; thus, the method of lipid extraction of food products becomes relevant for a more complete and valuable characterization of their nutritional value. The various methods of lipid determination for meat products are examined for their total recovery of these important lipid groups. A sequential extraction in conjunction with subsequent analytical methods is recommended.     

The cost of infant feeding in Liverpool, England

OBJECTIVE: To investigate feeding practices in infants under the age of 4 months in Liverpool, England with particular reference to the cost of infant feeding. DESIGN: A cross-sectional survey consisting of self-completion questionnaires and interviews. SETTING: Subjects' homes within Central and South Liverpool Primary Care Trust areas. SUBJECTS: One hundred and forty-nine women (aged 18 to 43 years) and their infants (mean age 13 weeks). RESULTS: The average weekly cost of breast-feeding was 11.58 pounds sterling compared with 9.60 pounds sterling for formula-feeding. Many breast- and formula-feeding women spent money however on items that were not needed or used only once or twice. This was especially true of first-time mothers. Characteristics significantly associated with higher spending were: feeding method - mothers that had or were partially breast-feeding (P=0.001), education - those educated to degree level (P=0.028), socio-economic status - those in social classes I and II (P=0.002) and age - those aged 30 years and over (P=0.003). CONCLUSIONS: This study demonstrates that while breast-feeding is often promoted as being free, this is not the case. Better information needs to be given to parents to avoid wasting money on items that are unnecessary, or where cheaper alternatives are available.